gpio: Add new flags to control sleep status of GPIOs

Add new flags to allow users to specify that they are not concerned with
the status of GPIOs whilst in a sleep/low power state.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
diff --git a/include/linux/gpio/driver.h b/include/linux/gpio/driver.h
index 3935828..af20369 100644
--- a/include/linux/gpio/driver.h
+++ b/include/linux/gpio/driver.h
@@ -213,6 +213,9 @@ bool gpiochip_line_is_irq(struct gpio_chip *chip, unsigned int offset);
 bool gpiochip_line_is_open_drain(struct gpio_chip *chip, unsigned int offset);
 bool gpiochip_line_is_open_source(struct gpio_chip *chip, unsigned int offset);
 
+/* Sleep persistence inquiry for drivers */
+bool gpiochip_line_is_persistent(struct gpio_chip *chip, unsigned int offset);
+
 /* get driver data */
 void *gpiochip_get_data(struct gpio_chip *chip);
 
diff --git a/include/linux/gpio/machine.h b/include/linux/gpio/machine.h
index c0d712d..13adadf 100644
--- a/include/linux/gpio/machine.h
+++ b/include/linux/gpio/machine.h
@@ -9,6 +9,8 @@ enum gpio_lookup_flags {
 	GPIO_ACTIVE_LOW = (1 << 0),
 	GPIO_OPEN_DRAIN = (1 << 1),
 	GPIO_OPEN_SOURCE = (1 << 2),
+	GPIO_SLEEP_MAINTAIN_VALUE = (0 << 3),
+	GPIO_SLEEP_MAY_LOOSE_VALUE = (1 << 3),
 };
 
 /**
diff --git a/include/linux/of_gpio.h b/include/linux/of_gpio.h
index 1e089d5..ca10f43 100644
--- a/include/linux/of_gpio.h
+++ b/include/linux/of_gpio.h
@@ -31,6 +31,7 @@ enum of_gpio_flags {
 	OF_GPIO_ACTIVE_LOW = 0x1,
 	OF_GPIO_SINGLE_ENDED = 0x2,
 	OF_GPIO_OPEN_DRAIN = 0x4,
+	OF_GPIO_SLEEP_MAY_LOOSE_VALUE = 0x8,
 };
 
 #ifdef CONFIG_OF_GPIO